In his recent blog, entitled “The Fourth Reactor and the Destiny of Japan”, Akio Matsumura correctly identifies the spent fuel pool in Unit 4 as the most serious potential threat for further massive radioactive releases from the Fukushima Daiichi nuclear power plant.

If not cooled by mechanical means for at least several years, the irradiated fuel in the spent fuel pool will overheat due to radioactivity alone. The heat generated by radioactivity must be removed as fast as it is being produced to keep the temperature of the nuclear fuel from soaring out of control.

In the last weeks, I have been speaking constantly with Japanese government and party leaders on this urgent issue. Surprisingly, most of them were not aware of the dangerous situation. I, along with many eminent scientists, are emphasizing the precarious situation of the fourth reactor that contains 1,535 nuclear fuel rods in the pool and is balanced on the second floor, outside of the reactor containment vessel. If the fuel rods spill onto the ground, disaster will ensue and force Tokyo and Yokohama to close, creating a gigantic evacuation zone. All scientists I have talked with say that if the structure collapses we will be in a situation well beyond where science has ever gone. The destiny of Japan will be changed and the disaster will certainly compromise the security of neighboring countries and the rest of the world in terms of health, migration and geopolitics. The Japanese government should immediately create an independent assessment team to determine the structural integrity of the spent fuel pool and its supporting structure. This is of the highest importance: the structure’s security is critical to the country’s future.

… these are not “dosimeters” but “glass badges” that passively collect radiation information. It won’t help these children or their parents to avoid high-radiation areas and spots, it won’t tell them how much radiation they will have been exposed unless they are sent in to a company to interpret the data.

Radiation exposure is increased by a factor of a trillion. Inhaling even the tiniest particle, that’s the danger.

Yo: So making comparisons with X-rays and CT scans has no meaning. Because you can breathe in radioactive material.

Hirose: That’s right. When it enters your body, there’s no telling where it will go. The biggest danger is women, especially pregnant women, and little children. Now they’re talking about iodine and cesium, but that’s only part of it, they’re not using the proper detection instruments. What they call monitoring means only measuring the amount of radiation in the air. Their instruments don’t eat. What they measure has no connection with the amount of radioactive material.

Dr. Helen Caldicott (Co-founder of Physicians for Social Responsibility):

You’ve bought the propaganda from the nuclear industry. They say it’s low-level radiation. That’s absolute rubbish. If you inhale a millionth of a gram of plutonium, the surrounding cells receive a very, very high dose. Most die within that area, because it’s an alpha emitter. The cells on the periphery remain viable. They mutate, and the regulatory genes are damaged. Years later, that person develops cancer. Now, that’s true for radioactive iodine, that goes to the thyroid; cesium-137, that goes to the brain and muscles; strontium-90 goes to bone, causing bone cancer and leukemia. It’s imperative … that you understand internal emitters and radiation, and it’s not low level to the cells that are exposed. Radiobiology is imperative to understand these days.”